In one proposed configuration of the power output apparatus, three rotational elements of a planetary gear unit are respectively connected to a crankshaft of an engine, a rotating shaft of a generator, and a driveshaft linked with an axle (see, for example, Patent Reference 1). A motor is linked to the driveshaft via a transmission. This power output apparatus corrects the engine output and the torque of the generator to assure a desired level of output torque, which is to be output to the driveshaft, during speed change of the transmission.
Patent Reference 1: Japanese Patent Laid-Open Gazette No. 2004-203220